1. Technical Field
The present invention relates to a device for charging an electric vehicle, and more particularly, to an in-cable control box for charging an electric vehicle not in a charging station and a scheduled charging method thereof.
2. Description of the Related Art
As environmental regulations have recently been strengthened, demand for environment-friendly electric vehicles has been increasing. However, an electric vehicle driven by a motor has a disadvantage in that the maximum mileage is shorter than that of an existing vehicle employing an internal combustion engine. In addition, since increase in battery capacity of the electric vehicle has a problem in terms of efficiency due to increase in the weight of the vehicle, frequent charging is performed instead of increasing the battery capacity. Therefore, there is a need for expansive establishment of charging infrastructure before broad distribution of electric vehicles.
An electric vehicle charging system can be classified according to charging methods, connection methods, and communication methods. The charging methods include a conductive charging method, an inductive charging method, and a battery swapping method. An electric connection device includes a connector corresponding to a lubricator and an inlet formed in an electric vehicle and corresponding to a gas inlet, and is classified into a single-phase or three-phase alternating current (AC) type, a direct current (DC) type, and a combo type for both AC and DC according to types of electric power. The communication methods between the charging system and the electric vehicle include a controller area network (CAN) method used in Japan and a power line communication (PLC) method preferred in the U.S. and Europe.
Among the charging methods of the electric vehicle, the conductive charging method is realized through electric connection and employs an AC charging stand or a DC charging device. The AC charging stand is not a charging device but a power supply that supplies AC power for charging, and actual charging is performed by an on-board charger in the electric vehicle. Such an AC charging stand inputs and outputs AC power having a commercial frequency.
As the AC charging stand, there are a self-standing charging stand and a portable in-cable control box (ICCB). The self-standing charging stand is very expensive as compared with the ICCB. Thus, the self-standing charging stand is generally used in a charging station and the ICCB is generally employed for family use.
As described above, the ICCB refers to a portable power supply that secures safety required upon charging of the electric vehicle with household electric power, and corresponds to a slow charging method where 7-8 hours are taken until charging is completed.
On the other hand, information about charging states of a conventional ICCB can be indicated in such a manner that a power light emitting diode (LED) flickers upon connection to an AC power source, a charging LED flickers during charging, and failure LED flickers when failure such as overcurrent, current leakage, and the like happens during charging. That is, a driver has no choice but to recognize a charging state indicated through just three color LEDs, and it is hard for the driver to recognize the current charging state in detail. Further, it is difficult and inconvenient for a driver to immediately recognize change in the charging state, if the driver does not look at the ICCB. In particular, when the failure LED flickers, there is no way to know what is wrong with the ICCB, and it is difficult and inconvenient for a driver to quickly cope with flickering of the failure LED.
Additionally, in the slow charging method, it is advantageous to use inexpensive midnight electric power or dump power. However, a conventional ICCB starts charging only in response to connection between the AC power and the connector and terminates charging only when the battery is fully charged. Therefore, when a driver performs charging at a specific time or to perform partial charging, there is inconvenience in that charging must be manually performed.
Korean Patent Publication No. 10-2011-0043731 (Apr. 27, 2011) discloses charging of an electric vehicle with an ICCB.